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The valorization of byproducts from the sugarcane industry represents a potential alternative method with a low energy cost for the production of metabolites that are of commercial and industrial interest. The production of exopolysaccharides (EPSs) was carried out using the yeast Suhomyces kilbournensis isolated from agro-industrial sugarcane, and the products and byproducts of this agro-industrial sugarcane were used as carbon sources for their recovery. The effect of pH, temperature, and carbon and nitrogen sources and their concentration in EPS production by submerged fermentation (SmF) was studied in 170 mL glass containers of uniform geometry at 30 °C with an initial pH of 6.5. The resulting EPSs were characterized with Fourier-transform infrared spectroscopy (FT-IR). The results showed that the highest EPS production yields were 4.26 and 44.33 g/L after 6 h of fermentation using sucrose and molasses as carbon sources, respectively. Finally, an FT-IR analysis of the EPSs produced by S. kilbournensis corresponded to levan, corroborating its origin. It is important to mention that this is the first work that reports the production of levan using this yeast. This is relevant because, currently, most studies are focused on the use of recombinant and genetically modified microorganisms; in this scenario, Suhomyces kilbournensis is a native yeast isolated from the sugar production process, giving it a great advantage in the incorporation of carbon sources into their metabolic processes in order to produce levan sucrose, which uses fructose to polymerize levan.

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BACKGROUND: The objective of the study was to evaluate the physicochemical characteristics and shelf-life of corn tortilla stored at room temperature (25 °C) using aw modifiers (propylene glycol and glycerol) and pH modifiers (fumaric acid and sodium benzoate) as preservatives combined with calcium hydroxide. Detection thresholds were used to determine the maximum preservative concentration and calcium hydroxide. Physicochemical characterization and sensory evaluation were used to determine the stability and sensory shelf-life of tortillas. RESULTS: Control, calcium hydroxide, calcium hydroxide + fumaric acid, calcium hydroxide + glycerol, calcium hydroxide + propylene glycol, and calcium hydroxide + sodium benzoate treatments had rounded half-lives of 1, 2, 1, 2, 2, and 2 days respectively. Glycerol combined with calcium hydroxide resulted in tortillas with lower pH variations over time. Mold presence was the critical attribute causing tortilla rejection. CONCLUSION: The use of aw modifiers had a better effect in preserving corn tortilla, as the concentration of pH modifiers at detection threshold levels was not able to reach an optimum performance when combined with calcium hydroxide. © 2021 Society of Chemical Industry.

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Rosins and turpentines present in pine resins have been widely used both industrially (coatings, electronics and paint) and pharmaceuticals (ointments). Among the main components of these matrices is abietic acid. This study focuses on the characterization and evaluation of the quality of rosins and turpentines in addition to the quantification of abietic acid in rosins. Rosin and spirit of turpentine were obtained separately through the distillation method from P patula and P. oocarpa resin, species grown in the Department of Cauca-Colombia. Resin-tapping was made using the traditional method (cup and gutter). Quality indicators were determined according to ASTM standards. Solubility tests and identification of functional groups were performed on the obtained rosin by ultraviolet-visible spectroscopy (UV-Vis), infrared (IR) and nuclear magnetic resonance (1H-NMR). The abietic acid present in the rosins was determined by high performance liquid chromatography (HPLC). According to their high acid value and low percentage of unsaponifiable matter, the extracted rosins are considered of medium-high quality. Quantification of abietic acid by HPLC showed 14.85 ± 0.24% and 16.09 ± 0.11% for P. patula and P. oocarpa rosin respectively.

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BACKGROUND CONTEXT: Many etiologies can lead to atlantoaxial subluxaion. In Grisel syndrome (GS), this subluxation occurs spontaneously after inflammatory processes of the head and neck. Diagnosis is typically based on clinical history and a strong suspicion of this syndrome. Nonsurgical treatment most often resolves the symptoms; however, in some cases surgical treatment is necessary to repair the subluxation. Various surgical techniques and instrumentation systems have been used to treat atlantoaxial subluxation, although there is no consensus regarding the best treatment method for the pediatric population. PURPOSE: To describe a case of atlantoaxial subluxation in a child with GS treated surgically with an alternative construct. STUDY DESIGN/SETTING: This is a case report and literature review. MATERIALS AND METHODS: Our case study involves a 5-year-old girl with a 6-month history of unresolved Fielding type II atlantoaxial subluxation caused by GS. Despite conservative treatment, the patient's symptoms continued to progress. After two failed closed reduction attempts, open reduction and C1-C2 fusion were performed with atlas laminar hook and axis pedicle polyaxial screws. A literature review of the surgical treatment of GS was also performed. RESULTS: After surgery, the patient exhibited full clinical and functional recovery with complete resolution of symptoms. At the 36-month follow-up examination, there was continual evidence of satisfactory reduction and fusion. No complications were observed. Upon completion of the literature review, eight GS cases were found to have been treated surgically with the minimum patient age being 9 years. CONCLUSIONS: Conservative management of GS is the most common and effective treatment; however, a few surgical cases have been reported in the literature with good results. Satisfactory clinical results and fusion at 36 months post surgery were seen in a pediatric patient with atlantoaxial subluxation and instability using atlas laminar hook and axis pedicle polyaxial screws.

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Study Design Case report. Objective Synovial cysts in the subaxial cervical spine are rare and are most commonly reported at the cervicothoracic junction. Only six cases of symptomatic C5-C6 synovial cysts have been reported in the literature; the condition is usually treated with decompressive laminectomy. We present a patient with a synovial cyst arising from the C5-C6 facet joint, associated with spondylolisthesis, and causing radiculomyelopathy. The patient was treated with a posterior excision of the cyst, decompressive laminectomy, and fusion. Methods A 67-year-old man had vertebral canal stenosis at C5-C6 secondary to a synovial cyst and spondylolisthesis with symptoms and signs of radiculopathy and myelopathy. Surgical management involved C5-C6 posterior decompressive laminectomy and excision of the cyst and C4-C6 instrumented fusion with lateral mass screws and rods. A literature review of symptomatic cervical synovial cysts is presented. Results The imaging studies identified grade I spondylolisthesis and a 3.3 × 4.3-mm extradural lentiform-like mass associated with focal compression of the spinal cord and exiting the C6 nerve root. After the surgery, the patient had an immediate full recovery and was asymptomatic by the 6-month examination. No operative complications were reported. The histologic report confirmed the presence of a synovial cyst. Conclusions C5-C6 is an unusual localization for symptomatic synovial cysts. Similar cases reported in the literature achieved excellent results after cyst excision and decompressive laminectomy. Because spondylolisthesis plus laminectomy are risk factors for segmental instability in the cervical spine, we report a case of a C5-C6 facet synovial cyst successfully treated with posterior laminectomy and C4-C6 fusion.